To investigate the effects of Reduning injection on immune function and inflammatory state in children with acute laryngotracheitis.Methods:A total of 50 children with acute laryngotracheitis diagnosed in The Second People's Hospital of Wuxi from May 2016 to May 2018 were divided into the observation group(n＝25）and the control group(n＝25）by randomized，single-blind and parallel control method.Both groups were given routine treatment，and the observation group meanwhile was given Reduning injection.The 2 groups were treated continuously for 5 d.The remission of clinical symptoms and clinical efficacy of the 2 groups were observed and statistically analyzed.The changes of immune function and inflammatory factors were detected and compared between the 2 groups.Results:The total effective rate of the observation group was 96.00%，which was significantly higher than that of the control group(76.00%)(P<0.05).Compared with the control group，the disappearance time of voice hiss，barking cough and inspiratory dyspnea of the observation group were significantly shorter(P<0.05 or P<0.01).Compared with before treatment，the levels of serum IgA and IgG in the 2 groups after treatment were significantly higher，and the levels of serum IgE were lower.The improvement of the observation group was better than those of the control group(P<0.05 or P<0.01).Compared with before treatment，the levels of serum CysLTs and ECP in the 2 groups were lower after treatment，and the levels in the observation group were significantly lower than those in the control group(P<0.01).Conclusion:Reduning injection can significantly alleviate the clinical symptoms of children with acute laryngotracheitis，at the same time，the regulation of immune function and inflammatory state of children is more prominent than that of Western medicine.